Biomathematics and computational approaches provided the foundation for many significant recent advances in HIV pathogenesis and are a critical component of work on genetic variation in HIV. The Annual International Discussion Meeting in HIV Dynamics and Evolution provides a forum for specialists in these approaches to present and discuss their latest results in depth in an informal setting. Topics addressed at recent meetings have included viral reservoirs for HIV, fitness of drug resistant variants, viral evolution in response to immune recognition, and the origin of global epidemic strains. The 9th Meeting in the series will be held at the UCLA Conference Center, Lake Arrowhead, California from March 17th - 19th 2002. The goals of the 9th Meeting will be: 1) To facilitate communication of the most recent results relating to a) HIV dynamics and pathogenesis, b) HIV evolution and phylogenetics, c) Immune responses, T cell dynamics and viral escape; 2) To provide a forum for debate and discussion of alternative hypotheses in these areas; 3) To integrate new biomathematical approaches into research in HIV pathogenesis and vaccine development. Participants in the 9th Meeting will include leading figures in virology, biomathematics, and evolution, as well as junior workers actively involved in research in these areas.